Wear runner for excavating bucket

ABSTRACT

A wear runner for an excavating bucket which includes a plurality of base elements secured to the bucket in end-to-end relation, a runner element for each base element removably mounted thereunder by means of a rearwardly divergent dovetail.

BACKGROUND AND SUMMARY OF INVENTION

This invention relates to a wear runner for an excavating bucket and,more particularly to a multipart runner which permits replacement ofwearable surfaces.

The buckets to which the instant invention has advantageous applicationare dragline buckets which are normally equipped with welded on runnerstrips. These strips extend along the bottom wall longitudinally fromthe open front of the bucket to the closed rear. Exemplary of runnerswhich have been used for many years are those seen in U.S. Pat. Nos.2,492,905 and 2,723,471. These runners were employed to protect thebottom wall of the bucket against undue wear but necessitatedconsiderable down-time when runner replacement was indicated. Othertypes of elements secured to bucket bottoms are those seen in U.S. Pat.Nos. 1,244,117 and 2,325,336.

The instant invention in providing replaceable runners makes use of adovetail connection between a wearable element and a base elementadapted to be generally permanently secured to the bucket bottom.Dovetail connections between a wearable part and a base part have beenemployed in excavating equipment previously. For example, a wear cap forone type of excavating tooth is seen in co-owned U.S. Pat. No. 2,896,345and a wear cap for a second type of excavating tooth is seen in co-ownedU.S. Pat. No. 3,082,555. In recent years, however, the dovetailconnection for wear caps has been discontinued for newer tooth designsas seen in co-owned U.S. Pat. Nos. 4,317,300 and 4,326,348.

The inventive dovetail connection differs from those employed previouslyin connection with tooth wear caps in having the dovetail surfacesdiverge so that the wearable element in the process of installation notonly becomes more tightly affixed to the base element but also movesupwardly and into closer contact therewith.

Other objects and advantages of the invention may be seen in the detailsof construction and operation set down in the ensuing specification.

The invention is described in conjunction with an illustrativeembodiment in the accompanying drawing, in which

FIG. 1 is a fragmentary perspective view of a dragline bucket as viewedfrom the bottom left side as viewed from the operator's perspective;

FIG. 2 is an exploded perspective view of the base and runner elementswith adjoining base elements shown fragmentarily and in phantom;

FIG. 3 is an enlarged longitudinal sectional view such as would be seenalong the sight line 3--3 of FIG. 1;

FIG. 4 is a perspective view of the base and wear elements of theinvention in the initial process of installation;

FIG. 5 is a view similar to FIG. 4 but showing the elements thereof infinal assembly;

FIG. 6 is a top plan view of the base element of the runner assembly;

FIGS 7 and 8 are sectional views taken, respectively, along sight lines7--7 and 8--8 as applied to FIG. 6;

FIG. 9 is a top plan view of the runner element of the invention;

FIG. 10 is a side elevational view such as would be seen along the sightline 10--10 as applied to FIG. 9; and

FIGS. 11 and 12 are fragmentary sectional views such as would be seenalong the sight lines 11--11 and 12--12 as applied to FIG. 1.

DETAILED DESCRIPTION

In the illustration given and with reference first to FIG. 1, thenumeral 20 designates generally a dragline bucket having a pair ofopposed sidewalls 21, a rear wall 22 and an open front 23. The rear wallmerges into a bottom wall 24 which terminates in the open front 23. Dragchains as at 25 are connected to the forward ends of the sidewalls 21and hoist chains 26 are connected to an intermediate part of thesidewalls 21.

The forward edge or lip of the bottom wall 24 is equipped with aplurality of forwardly projecting excavating teeth 27. The foregoingconstruction is generally conventional and is set down for explainingthe environment of the invention.

The numeral 28 designates generally a longitudinally extending runner ofwhich a plurality are provided in transversely spaced relation on thebottom wall 24 of the bucket 20.

Each runner assembly includes a plurality of base elements 29 (see FIG.2) which are welded to the underside of the bucket in serial orlongitudinally aligned relation. In FIG. 2 the adjacent forward baseelement is seen fragmentarily and in phantom and is designated 29a. Thebase element immediately rearward of the solid line depiction in FIG. 2is also shown fragmentarily and is designated by the numeral 29b.

For each base element 29 I provide a runner element 30--also seen inperspective in FIG. 2.

As can be appreciated from a consideration of FIG. 3, a plurality ofbase elements 29 are secured as by welding to the bottom wall 24 andextending around onto the back wall 22. These are arranged in end-to-endgenerally abutting relation so as to form, in effect, a continuous railfor the receipt of a similar plurality of the runner elements 30.

In the illustration given, each runner element is installed by movementtoward the base element 29, i.e., in the direction of arrow 31 in FIG.2. Thereafter, the runner element 30 is slid rearwardly as in thedirection of the arrow 31 applied to FIG. 4. Ultimately, the runnerelement 30 extends rearwardly beyond the base element 29 a shortdistance as is shown in FIG. 5. This results in a secure lock developedby the divergent dovetail-shaped walls which will be described ingreater detail hereinafter.

End Locks

After the runner elements 30 have been installed as seen in FIGS. 1 and3, I secure the same in position by means of welding a series of blocks32 at the front of the most forward runners 30 and rearward of the teeth27. More particularly, the blocks or stops 32 are welded between twoadjacent base elements 29 so that one block or stop can effectively be ablock for two runner elements--the actual installation having runnersmore closely located than illustrated in FIG. 1.

It will be appreciated that the normal forward movement of the draglinebucket 20 exert a rearward or setting force on each of the runnerelements 30. It is only in the unusual circumstance where the bucket isdragged rearwardly against the ground where an unseating force for therunner elements is encountered. Thus, there is not required a stronglock or block to maintain the runner elements in place. Also, byutilizing a readily removable block, removal and replacement of therunner elements 30 is facilitated.

Also to protect the replaceable runners against the unusual backwarddrag of the bucket 20, I provide a guard 33--seen only in FIG. 3 and atthe left hand side thereof. This, advantageously, may be half of an 8"steel pipe, split longitudinally. This projects downwardly to mask therear most runner element 30 to prevent the same from being "peeled" offby the abnormal backward movement of the bucket.

Base Element Details

The base element 29 is seen in FIGS. 6-8 and includes a relativelyelongated, plate-like body. The rear end 34, i.e., the end positionedtoward the rear of the bucket when installed, is laterally enlarged toprovde arms 35. These provide safety stops for the runner element 30 ascan be appreciated from a consideration of FIGS. 5.

Each of the longitudinal sides 36 of the body 33 is equipped withlongitudinally spaced pairs of divergent dovetail surfaces as at 37, 38,39 and 40. The dovetail shape is developed by a downward and outwardflare as can be appreciated readily from a consideration of FIGS. 7 and12. The flare or angle is about 30° relative to the vertical. Thedivergence--in proceeding rearwardly is of the order of about 15°relative to the longitudinal axis, i.e., the axis along which the runnerelement 30 is moved for installation as indicated by the arrow 31 ofFIG. 4. The slope and divergence provide for an especially advantageousmounting of the runner elements 30 on the base elements 29--as therunner elements move more rearwardly they ride up the slope of thesurfaces 37-40 to pull the runner element 30 closer and closer to thebase element 29. The arms 35 provide a safety stop when the clearancebetween the confronting dovetail surfaces on the two elements is largerthan normal. The confronting surfaces on the runner element 30 areclearly seen in FIG. 9 and are designated by the numerals 37', 38', 39'and 40'--corresponding to the surfaces on the base element which theyconfront.

Runner Element Details

Referring particularly to FIGS. 9 and 10, the runner element 30 is againa generally platelike body and is generally rectangular in planproviding a lower face 41 which, when installed, rides against theground. The upper face 42 is rabbeted or grooved so as to receive thebase element 29--see particularly FIG. 12 where the numeral 43designates the base of the rabbet.

As indicated previously, the confronting surfaces 37'-40' on the runnerelement 30 are disposed substantially identically to those provided onthe base element 29, i.e., the surfaces 37-40. In both elements, thesurfaces are arranged in two longitudinally spaced apart pairs with thesurfaces in each pair being on opposite sides. This effectively cutsdown the amount of movement needed for installation. Inasmuch as eachsurface, for example, the surface 37, has an axial length of about23/4", it is only needed to move the runner element 30 this distance forseating--yet the dovetail or wedging action achieved is that equivalentto twice the amount, viz., 51/2". To achieve this advantage, I equip thebase element 33 with opposed notches as at 44 and 45. This permits theentry of the portions of the runner element carrying the surfaces 39'and 40' in the fashion indicated in FIG. 4.

In the same fashion, I provide opposed notches as at 46 and 47 in therunner element 30 for the accommodation of the portions of the wearelements 29 carrying the dovetail surfaces 37 and 38--again see FIG. 4.When installed, these notches are aligned as can be appreciated from aconsideration of FIG. 5.

I also provide a slight relief down the center of the rabbet as at48--see particularly FIG. 12. This insures that the central portion ofthe rabbet is not higher than the sides in bearing as at 43.

The upper face 42 of the runner element 30 extends only partway of thelength of the element so as to develop a shoulder as at 49 (see FIG. 10)which can cooperate with the arms 35 in the fashion indicated in theright hand portion of FIG. 5. The remainder of the rearward portion asat 50 extends beyond the associated base element 29 into underlyingrelation with the next rearward base element--see particularly theelements 29 and 29b of FIG. 3. The extreme rearward end of each runnerelement as at 51 is curved so as to conform with the forward end 52 ofthe adjacent element--see also FIG. 3.

The bottom 24 of the bucket 20 is not flat but slightly arcuate andtherefore the same type of curvature is provided in the elements 29 and30--compare FIGS. 8 and 10.

Where the elements are at the "corners" of the bucket, i.e., thejunction of the sidewalls 21 and the bottom wall 24, I providetransversely arcuate elements as at 129 and 130 as illustrated in FIG.11. Again there is provided a relief as at 148. However, the operationis identical to that previously described with respect to the moreflatter elements.

OPERATION

The invention provides replaceable wear runners for excavating equipmentsuch as a dragline bucket 20 (see FIG. 1). The replaceable runners 28take the place of the conventional weld on strips of the prior art. Eachrunner 28 includes a series of base elements 29 (see FIG. 2) which arewelded to the bottom wall 24 of the bucket 20--as at 29a, 29, 29b, etc.in FIG. 3. The runners 28 normally will extend rearwardly up onto therear wall 22 which merges gradually into the bottom wall 24.

After the base elements 29 have been installed, the runner elements 30are installed in sequence. For example, in FIG. 3, the left most runnerelement 30 is installed by placing the runner element on the baseelement in the configuration depicted in FIG. 4. The base element 29 ineffect provides the Tenon which is received within the mortise of therunner element 30. The Mortise M or rabbet is defined by sidewalls as atM' (still referring to FIG. 4) which diverge in proceeding rearwardlyand which also are sloped or flared downwardly and outwardly to providea dovetail fit with correspondingly contoured surface on the baseelement 29.

The sloping divergent sidewalls provide dovetail surfaces arranged intwo longitudinally spaced pairs with the surfaces in each pair being onopposite sidewalls--see, for example in FIG. 9 the forward pair 37' and38' and the more rearward pair 39' and 40'. The rearward divergence, inthe illustration given, is about 15° from the longitudinal axis and theslope or flare is about 30° to the vertical--see particularly FIG. 12.By providing the separate pairs of connecting or bearing surfaces, I amable to install the wear runner with limited movement--a movement ofapproximately 3" can yield a bearing length of about 6". To accomplishthis, notches are provided between the pairs of bearing surfaces as 46and 47--see FIG. 4.

The base element 29 is equipped with laterally extending arms as at 35which provides safety stops for the rearward movement of the runnerelement 30. In some instances, the confronting bearing surfaces on thebase element 29--as at 37-40--can become worn after a number ofreplacement runner elements have been installed and therefore there isthe possibility that the runner element would move too far rearwardly.This is prevented by the cooperation of the arms 35 and the shoulders 49provided on the runner element 30.

To complete the operation, I provide a forward stop at 32 (see the righthand portion of FIG. 3) which prevents the runner elements from beinginadvertently detached should the bucket be dragged rearwardly. Also, Iprovide a guard or mask for the rear end of each runner in the form ofthe guard 33 which prevents a rock or the like from being hooked on theprojecting part 50 of the runner element 30 and therefore constitutes apotential means for stripping off the runner element.

Replacement is readily achieved merely by burning off the block orblocks 32 and removing some or all of the runner elements 30 which havebecome unduly worn. This can be done readily in the field with a minimumof downtime--which is important inasmuch as the buckets in question areused in remote, often primitive places and because of their size 50-150cubic yards capacity, are expensive to pull out of work. Also, theinvention provides readily handleable elements. For example, for abucket of the size indicated, each runner element 30 is approximately16" long, approximately 13" wide and approximately 4" in thickness. Bysegmenting the runner, not only are the replacement elements morehandleable but also can approximate the curvature of the bucketreadily--as contrasted to taking a corresponding long runner strip andforming it to the curvature of the bucket.

The invention is additionally advantageous in that the base elements 29which are welded together longitudinally provide bottom support for thebasket portion of the bucket--thereby eliminating the need foradditional supports for this purpose. Additionally, the back stop 33provides lateral support for the bucket as do the stop blocks 32 weldedacross the front of the base elements 29.

While in the foregoing specification a detailed description of anembodiment of the invention has been set down for the purpose ofillustration, many variations in the details hereingiven may be made bythose skilled in the art without departing from the spirit and scope ofthe invention.

I claim:
 1. A wear runner for an excavating bucket or the like defininga longitudinal direction extending from a mouth portion of the bucket tothe rear of the bucket comprising a plurality of base elements securedadjacent one another to said bucket in end-to-end relation in thelongitudinal direction, each base element having divergent sloped sideedges, a runner element for each base element and equipped with aplurality of runner element mounting means enabling the mounting of saidrunner elements serially on said base elements by sliding in thelongitudinal direction, said mounting means including upstandingrearwardly divergent, sloped side shoulders dovetailed with said baseside edges, and stop means secured to said bucket maintaining saidrunner elements in assembled fashion.
 2. The runner of claim 1 in whicheach element has a pair of spaced apart dovetail surfaces on each side.3. The runner of claim 2 in which each runner element is equipped withan inwardly extending notch between each pair of spaced apart dovetailsurfaces to accommodate receipt of a portion of the base element sideincident to assembly.
 4. The runner of claim 3 in which each baseelement is equipped with a laterally enlarged end portion.
 5. The runnerof claim 4 in which each runner element has a flange-like projectionextending under and beyond said laterally enlarged end portion of saidbase element.
 6. A dragline bucket runner construction for a buckethaving a bottom wall, said bottom wall extending longitudinally from theclosed rear to the open front of the bucket, a plurality oflongitudinally extending, transversely spaced runner assemblies mountedon the exterior of said bottom wall, each runner assembly comprising:aplurality of base elements welded to said bottom wall in series fashion,each base being rearwardly divergently rabbeted to provide adovetail-shaped tenon, a runner element correspondingly rabbeted toprovide a dovetail-shaped mortise slidingly mounted on each baseelement, and block means at the front of each runner assemblymaintaining said elements in assembled fashion.
 7. An assembly ofreplaceable runner elements for a bucket or the like comprising aplurality of unitary generally rectangular, relatively elongated bodieseach having a lower face adapted to engage the ground when the elementsare installed in end to end relation and an upper face adapted to beconnected to a bucket, said upper surface having a longitudinallyextending rabbet providing two longitudinally spaced apart pairs ofopposed dovetail-shaped mounting surfaces, the surfaces in each pairbeing longitudinally divergent.
 8. The replaceable runner element ofclaim 7 in which said upper face terminates short of the lower face toprovide a stop-engagable shoulder.
 9. The replaceable runner element ofclaim 8 in which said opposed mounting surfaces are divergent in thedirection of said shoulder.
 10. The replaceable runner element of claim7 in which said runner element has a longitudinal axis along which saidelement is moved in being installed, said surfaces being disposed at aminor acute angle to said axis, and a pair of opposed notches in saidrabbet between said surface pairs.
 11. A replaceable wear runner elementfor a dragline bucket or the like comprising unitary relativelyelongated plate-like body having forward and rear ends and anundersurface adapted to engage the ground, said body having an uppersurface adapted to be positioned in confronting relation to theunderside of a bucket, said upper surface at its forward end beingequipped with laterally spaced integral upstanding portions providingconfronting interior walls, said walls being arranged in twolongitudinally spaced pairs separated by a notch in each wall, saidwalls being rearwardly divergent at an angle of about 30°, each wallbeing downwardly and outwardly sloped at an angle of about 30° to thevertical, parts of the walls in one pair being longitudinally alignedwith corresponding parts of the walls in the other pair, said upstandingportions terminating a spaced distance from said body rear end.
 12. Thereplaceable wear runner element of claim 11 in which said notches eachhave a longitudinal extent approximately the same length as that of eachof said walls.